Automatic safety-belt sign



F 1960 K. DAWKINS ET AL 2,

AUTOMATIC SAFETY-BELT SIGN Filed March 12, 1956 ATTORNEYS.

United States Patent Q 2,924,817 AUTOMATIC SAFETY-BELT SIGN Kenneth Dawkins, Minneapolis, and William C. James, Wayzata, Minn., assignors to Franklin Manufacturing Company, Inc., Minneapolis, Minn., a corporation of esota Application March 12, 1956, Serial No. 570,905 Claims. (Cl. 340-377) This invention relates in general to automatic timing systems and more particularly to an improved system for energizing an electrical circuit for a given period of time and for automatically de-energizing the electrical circuit at the end of said given period of time.

Accordingly, it is an object of this invention to provide an improved timing system.

Itis a further object of this invention to provide an improved timing system which automatically initiates an information display operation in a vehicle.

It is a still further object of this invention to provide an improved timing system which automatically terminates the information display operation after a predetermined period of time.

It is another object of this invention to provide an improved timing system which is simple, inexpensive and requires relatively few moving parts and is adaptable to existing vehicles.

With these and other objects in view, the invention consists in the construction, arrangement and combination of the various parts of the novel automatic timing system whereby the objects contemplated are attained is hereinafter set forth. The various features of novelty which characterize this invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding ofthe invention, however, and its advantages, reference is had to the accompanying drawing and descriptive matter in which is illustrated and described a specific illustrative embodiment of the invention.

In the drawing:

Figure 1 is a pictorial view of the interior of a vehicle showing an information display device in accordancewith the invention;

Figure 2 is a schematic diagram of the electrical circuit of one embodiment of the automatic timing system;

Figure 3 is a schematic diagram of the electrical circuit of another embodiment of the automatic timing system; and

Figure 4 is a schematic diagram of the electrical circuit of still another embodiment of an electrical timing system.

Referring now to the drawing, there is shown in Figure 1 the interior of a passenger carrying vehicle which advantageously may be an automobile, a bus, or the like. A housing 1, preferably with an illuminating means such as a filament lamp positioned therewithin, is mounted within the vehicle such that the information to be displayed is within the line of sight of the passengers. This information, such as-No Smoking, Fasten Safety Belts, or any other information which it is desired to call to the attention of the passengers. It has been found that housing 1 advantageously may comprise a semi-flexible plastic such as polyethylene, for attachment to the visor or windshield, or alternatively may comprise a metal chassis if rear-dash window mounting is desired.

In accordance with an aspect of this invention, the

as desired, may be statements.

information display device is illuminated for a predetermined period of time starting at the time the operator of the vehicle places the key into the ignition switch for beginning operation of the vehicle. One circuit for carrying out this object is shown in Figure 2 of the drawing and comprises a source of potential 10 which advantageously may be a battery normally forming the part of the vehicle electrical system. One terminal of battery 10 is connected to a contact 11 of the ignition switch 12. The other contact 13 of ignition switch 12 is connected through a resistance 41 to the other terminal of battery 10. Also connected to contact 13 of ignition switch 12 are filaments 14 and 15 of illuminating devices or lamps 16 and 17 respectively. Connected to the other side of the filaments 14 and 15 is a bimetal member 18 which is held in normally closed relation with a contact 19 connected to said other end of source of potential 10.

The bimetal member 18 may be of any type well known in the art and advantageously comprises the combination of two strips of metal each having a different temperature coetficient of expansion. Thus, as is well understood, when the temperature of the bimetal member is increased, one of the metal strips will expand a different amount than the other and thereby cause the bimetal member to curve upwardly away from contact 19 thereby to open the circuit to lamps 16 and 17.

In the operation of the device, the automobile ignition switch 12 is closed by the operator when he first puts the vehicle into motion. This action completes a first circuit through resistance 41 and completes a second circuit through the lamps 16 and 17 and the bimetal member 18. Thus, at this time the information which it is desired to display is illuminated and called to the attention of the passengers of the vehicle. As the current continues to flow through resistance 41 and heat is generated and radiates therefrom to the bimetal member 18, the latter expands and moves away from the contact 19 to open the circuit of lamps 16 and 17 and darken the information display device. The bimetal member 18 will remain in the open position as long as the current is allowed to flow through resistance 41 or until the ignition switch 12 is returned to the off position.

In accordance with a feature of timing characteristics of the the value of the resistance 41, the voltage value of potential source 10, the spacing between the resistance 14 and the bimetal member 18, the material used to fabricate bimetal member 18 and the tension which is applied to the bimetal member. Thus any desired timing interval may be attained by properly adjusting one or more of these factors. Advantageously, resistance 41 is made variable for ready and simple adjustment of the timing interval.

Figure 3 of the drawing shows another embodiment of the automatic timing system which utilizes the bimetal member itself as the heating element. This circuit comprises a source of potential 20, one terminal of which is connected to contact 21 of ignition switch 22. The other contact 23 of ignition switch 22 is connected through a resistance 24 to one end of the bimetal member 25. A contact '26 is positioned a spaced distance away from the said one end of bimetal member 25, which contact is connected to the other terminal of potential source 20. A pair of lamps 27 and 28 shown connected in parallel in Figure 3 may be connected between contacts 23 of the ignition switch 22 and contact 29, which is held in normally closed relation with contact 26.

In the operation of this embodiment of the invention, when ignition switch 22 is closed by the operator curthis invention, the circuit are controlled by 

